The markets experienced a very volatile week due to the financial calamity playing itself out in the Eurozone regarding the small island of Cyprus. Oil prices rose early in the week, only to correct this rise midweek and then reverse once again towards the end of the week and re-rally. The overall market, as measured by the S&P 500 index, seemed unable to establish a trend. Each day this week saw alternating cycles of rallies and corrections. It was a traders' paradise, but a long-term buy and hold investor saw significant swings in their portfolio values on a daily basis. Overall though, the index did close higher on Friday than where it ended the week. As usual, this market noise had different effects on the six foreign integrated oil and gas companies that I follow in this series.

Statoil (NYSE:STO) opened at $24.23 on March 18, 2013. The stock closed at $24.57 in after hours trading on March 22, 2013. Stockholders in the company thus saw the value of their holdings increase by $0.34 per ADR share or 1.40% over the week. Statoil opened at $25.70 on February 25, 2013. This gives the stock a trailing four-week loss of $1.13 per share or 4.40%. Statoil was awarded fifteen leases in the Gulf of Mexico this week. These leases have, if oil is discovered on the blocks, the potential to further reinforce Statoil's reserve development which was a weak point for the company until recently. If Statoil discovers oil or gas at these locations, it may also contribute to the company's forward production growth, thus potentially increasing profits. Statoil also discovered a third natural gas field off of the coast of Tanzania. This further increases Statoil's reserves and makes the nation's resource development an even more promising opportunity than it was previously.

STO 5-Day Chart

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Source: Fidelity Investments

STO 4-Week Chart

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Source: Fidelity Investments

BP plc (NYSE:BP) opened the week at $40.76. The stock closed at $42.01 in after hours trading on March 22. BP's stockholders thus saw the value of their holdings increase by $1.25 or 3.07% over the week. BP opened at $41.17 on February 25, 2013. Thus, shareholders of BP stock saw the value of their holdings increase by $0.84 per share or 2.04% over the trailing four-week period. BP will be buying back $8 billion worth of stock, following the completion of the sale of its troubled Russian joint-venture TNK-BP. In theory, this should drive the stock price higher but, historically, buybacks have not always had that effect. BP's legal troubles due to 2010's Macondo disaster also continued this week, with the charges against M-I LLC and Cameron International being dismissed by the federal judge overseeing the trial.

BP 5-Day Chart

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Source: Fidelity Investments

BP 4-Week Chart

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Source: Fidelity Investments

Total S.A. (NYSE:TOT) opened on March 18 at $49.94 per share. The stock closed at $49.60 in after hours trading on March 22. This gives the stock a trailing five-day loss of $0.34 per share or 0.68% for the week. Total opened on February 25, 2013 at $51.76. Thus, stockholders have seen the value of their holdings decrease by $2.16 per share or 4.17% over the past four weeks.

TOT 5-Day Chart

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Source: Fidelity Investments

TOT 4-Week Chart

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Source: Fidelity Investments

Suncor (NYSE:SU) opened on March 18 at $30.35. The stock closed at $30.28 in after hours trading on March 22. This gives the stock a loss of $0.07 per share or 0.23% for the week. The stock opened on February 25, 2013 at $31.64. Thus, Suncor stock has seen a trailing four-week loss of $1.36 per share or 4.30%.

SU 5-Day Chart

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Source: Fidelity Investments

SU 4-Week Chart

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Source: Fidelity Investments

Royal Dutch Shell (NYSE:RDS.A) opened at $65.36 on March 18, 2013. The stock closed at $65.72 in after hours trading on Friday, March 22. Shareholders thus saw the value of their holdings increase by $0.36 per share or 0.55% for the week. The stock opened at $65.94 on February 25, 2013. Shareholders thus saw the value of their holdings decrease by $0.22 per share or 0.33% over the trailing four-week period.

RDS.A 5-Day Chart

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Source: Fidelity Investments

RDS.A 4-Week Chart

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Source: Fidelity Investments

Eni (NYSE:E) opened at $46.37 on February 19. The stock closed at $47.20 in after hours trading on Friday, March 22. Shareholders thus saw the value of their holdings increase by $0.83 per share or 1.79% for the week. The stock opened at $47.61 on February 25, 2013. Shareholders thus saw the value of their holdings decrease by $0.41 per share or 0.86% over the trailing four-week period. Eni announced the discovery of its ninth oil find off of the coast of Angola this week. This new discovery could have the potential to produce approximately 5,000 barrels of oil per day. While that is certainly not a large boost to Eni's production, it will still potentially increase the company's revenues once developed.

E 5-Day Chart

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Source: Fidelity Investments

E 4-Week Chart

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Source: Fidelity Investments

These six stocks delivered a mixed performance over the past week. Two of the companies' stocks delivered paper losses to investors and the remaining four delivered gains. The best performer by far over the past week was BP. Both Statoil and Eni also delivered respectable performances over the past week. Meanwhile, Total was the worst performer, although neither Total nor Suncor (the other loser) delivered a significant loss. It is a bit of a different story when we look at the trailing four week performances of these six stocks. BP was the only one of the six to see its share price increase over the trailing four-week period. The remaining five stocks each saw share price declines over the period. The worst performer of these was Statoil with Suncor in a very close second. Statoil has historically been a relatively stable stock so this decline could be a buying opportunity. I still believe that Suncor is undervalued at these prices as well.

Disclosure: I am long STO, BP, SU. I wrote this article myself, and it expresses my own opinions. I am not receiving compensation for it (other than from Seeking Alpha). I have no business relationship with any company whose stock is mentioned in this article.